The present invention relates to an apparatus for detecting an operation mode of a tape cassette player into which a cassette tape is loaded so as to record and reproduce information and, more particularly, to an apparatus for detecting an operation mode of a tape cassette player which can also detect whether the tape cassette loaded into the player is available for recording.
For example, as shown in FIG. 1, a tape cassette used for a video tape cassette recorder comprises a groove 2 formed in one side of the rear body of a cassette 1 and an erase-prevention tab 3 formed to obstruct groove 2. That is, a tape cassette having erase-prevention tab 3 is available for recording by the operation of a player, while a tape cassette in which erase-prevention tab 3 has been removed cannot be used for recording.
A player which employs tape cassette 1 comprises means for allowing or prohibiting a recording mode by detecting whether the erase-prevention tab 3 is present. That is, the purpose of providing the means for allowing or prohibiting a recording mode is to prevent the unintentional erasure of information due to user error, for example, via player misoperation.
Meanwhile, a cassette player comprises a mode discriminator for recognizing the current state of the deck mechanism for driving a tape cassette, and for precisely changing the state to a desired mode when a user wants another mode.
FIG. 2 roughly illustrates the related components provided in a conventional VCR deck mechanism. The VCR deck mechanism comprises an erase-prevention sensor lever 5 which is tension-biased by a spring 6 so as to contact erase-prevention tab 3 and pivot-supported so as to change the rotating location depending on the presence of erase-prevention tab 3 in one side of a deck 4, and a switch 7 which opens or closes a switching contact by interlocking with erase-prevention sensor lever 5. That is, when erase-prevention tab 3 is attached to tape cassette 1 loaded into deck 4, a protruding portion 5a of sensor lever 5 is pushed back. On the contrary, the removal of erase-prevention tab 3 allows protruding portion 5a of sensor lever 5 to be inserted into groove 2, so that the rotating location of sensor lever 5 changes in accordance with the presence or absence of erase-prevention tab 3. Thus, switch 7 is operated by an extending portion 5b of detecting lever 5. Accordingly, the tape player allows or prohibits a recording mode depending on whether the contact of switch 7 is opened or closed.
Moreover, referring to FIG. 2, a motor 8 is installed at one side so as to change the state of the deck mechanism depending on the deck mechanism mode, a master gear 9 rotates by the operation of motor 8, and a slide member 10 moves by the operation of master gear 9. The deck mechanism is changed to a state where each operation mode can be performed in accordance with the degree of the movement of slide member 10.
In the above-noted deck mechanism, the changed or converted operation mode can be discriminated by detecting the distance of the movement of slide member 10. Since slide member 10 moves by the rotation of master gear 9, the converted operation mode can be discriminated by detecting a rotation angle of master gear 9. Accordingly, in the deck mechanism, as shown in FIG. 2, an operation mode of the master gear 9 depending on a rotation angle is recognized by installing a rotary-type switch 11 on master gear 9.
In the technique as described above, the product cost is higher due to the increased number of parts and the resulting increased working time, since the two separate switches 7 and 11 are needed in order to detect whether the erase-prevention tab of a cassette tape is removed and to discriminate the operation mode of a deck mechanism.